U.S. patent number 9,295,460 [Application Number 12/347,831] was granted by the patent office on 2016-03-29 for anchors and method for securing suture to bone.
This patent grant is currently assigned to Cayenne Medical, Inc.. The grantee listed for this patent is Jordan A. Hoof, Kevin S. Nason. Invention is credited to Jordan A. Hoof, Kevin S. Nason.
United States Patent |
9,295,460 |
Hoof , et al. |
March 29, 2016 |
Anchors and method for securing suture to bone
Abstract
A method for securing suture to bone comprises drilling a hole
in a desired portion of bone at a desired procedural site, passing
a strand of suture through a portion of soft tissue to be
approximated to the portion of bone, and extending the free suture
ends proximally from the soft tissue. The suture is loaded into an
anchor implant. Using an inserter, on a distal end of which is
attached the anchor implant, the anchor implant is manipulated into
the bone hole. The suture is then tensioned to a desired level by
pulling on the free suture ends, after the anchor implant is
positioned in the bone hole. The free suture ends are wrapped about
a suture cleat on an inserter handle once the desired tension level
is achieved. A proximal anchor component is moved distally to
engage with a distal anchor component to lock the anchor in place
within the bone hole, and to lock the suture in place within the
anchor. Then, the inserter is removed from the procedural site.
Inventors: |
Hoof; Jordan A. (Cave Creek,
AZ), Nason; Kevin S. (Chandler, AZ) |
Applicant: |
Name |
City |
State |
Country |
Type |
Hoof; Jordan A.
Nason; Kevin S. |
Cave Creek
Chandler |
AZ
AZ |
US
US |
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Assignee: |
Cayenne Medical, Inc.
(Scottsdale, AZ)
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Family
ID: |
41464954 |
Appl.
No.: |
12/347,831 |
Filed: |
December 31, 2008 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20100004683 A1 |
Jan 7, 2010 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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61018316 |
Dec 31, 2007 |
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61018353 |
Dec 31, 2007 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B
17/0401 (20130101); A61B 2017/0414 (20130101); A61B
2090/037 (20160201); A61B 2017/0456 (20130101); A61B
2017/0427 (20130101); A61B 2017/0453 (20130101); A61B
2017/0496 (20130101); A61B 2017/0412 (20130101); A61B
2017/0409 (20130101) |
Current International
Class: |
A61B
17/04 (20060101) |
Field of
Search: |
;606/139,144,232 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
International Search Report, corresponding to PCT Application No.
PCT/US2009/47570, filed Jun. 16, 2009, International Searching
Authority, Oct. 2, 2009. cited by applicant.
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Primary Examiner: Anderson; Gregory
Attorney, Agent or Firm: Stout; Donald E. Stout, Uxa &
Buyan, LLP
Parent Case Text
This application claims the benefit under 35 U.S.C. 119(e) of the
filing date of Provisional U.S. Application Ser. No. 61/018,316,
entitled Anchor for Securing Suture to Bone, filed on Dec. 31,
2007, and of the filing date of Provisional U.S. Application Ser.
No. 61/018,353, entitled Devices, Systems, and Methods for Material
Fixation, also filed on Dec. 31, 2007. Each of these prior
provisional applications are expressly incorporated herein by
reference, in their entirety.
Claims
What is claimed is:
1. An anchoring system for securing suture to bone, comprising: an
implant comprising a suture securing aperture extending
transversely through the implant from at least one side thereof,
having a distal tip and a proximal end, and having external surface
features for securing the implant within surrounding bone; a
proximal member, having a proximal end which is proximal to the
proximal end of the implant, said proximal member being movable
distally to engage said implant and to fix the suture in place
within said implant and relative to the bone; said implant further
comprising an internal suture cavity having a tapered surface and
extending axially along the implant, wherein one leg of a length of
suture running through said implant extends axially along an
external side of the implant, and a second leg of the length of
suture is compressed against the proximal member and along the
tapered edge of the internal suture cavity, axially along the
internal suture cavity; and an inserter which is engaged with said
proximal member to move said proximal member distally to engage
said implant, and is removably connected to the proximal end of
said implant; wherein said implant and said proximal member have
mating surfaces which lock together when the implant and the
proximal member are fully engaged.
2. The anchoring system as recited in claim 1, wherein said
proximal member comprises a screw member.
3. The anchoring system as recited in claim 1, wherein said
proximal member comprises a wedge member.
4. The anchoring system as recited in claim 1, wherein said
transverse suture securing aperture comprises a suture eyelet which
extends entirely through a transverse width of the implant.
5. The anchoring system as recited in claim 1, and further
comprising an engagement tube for coupling the proximal member and
the implant to the inserter.
6. The anchoring system as recited in claim 1, and further
comprising a handle portion connected to a proximal end of the
inserter.
7. The anchoring system as recited in claim 1, and further
comprising internal surface texturing disposed within said implant
at a pinch point within said implant, for improving suture
retention after fixation.
8. The anchoring system as recited in claim 1, and further
comprising a suture channel on an external surface of said implant
for permitting the suture to slide freely along said external
surface for tissue tensioning.
9. The anchoring system as recited in claim 1, and further
comprising an internal thread in said implant.
10. The anchoring system as recited in claim 1, and further
comprising snap features for securing said mating surfaces
together.
11. The anchoring system as recited in claim 1, and further
comprising a suture channel disposed on one of said mating
surfaces.
12. The anchoring system as recited in claim 1, wherein said
implant and said proximal member are configured to be complementary
in shape, so that when the proximal member and the implant are
engaged, an enlarged implant is created which has an external
surface comprised substantially equally of external surfaces of
each of the implant and the proximal member.
13. A method for securing suture to bone, comprising: drilling a
hole in a desired portion of bone at a desired procedural site;
passing a strand of suture through a portion of soft tissue to be
approximated to said portion of bone, and extending the free suture
ends proximally from the soft tissue; loading the suture into a
distal anchor implant having external surface features for securing
the implant within surrounding bone; using an inserter, on a distal
end of which is attached the distal anchor implant, to manipulate
the distal anchor implant into the bone hole; tensioning the suture
to a desired level by pulling on the free suture ends, after the
distal anchor implant is positioned and anchored in place within
the bone hole; wrapping the free suture ends about a suture cleat
on an inserter handle once the desired tension level is achieved;
moving a proximal anchor implant distally, from a position wherein
a proximal end of the proximal anchor implant is proximal to a
proximal end of the distal anchor implant, to engage the proximal
anchor implant with the distal anchor implant to lock the anchor in
place within the bone hole, and to lock the suture in place within
the anchor, so that one leg of a length of suture running through
the implant extends axially along an external side of the implant,
and a second leg of the length of suture is compressed against the
proximal anchor implant and along a tapered edge of an internal
suture cavity disposed within the distal anchor implant, axially
along the internal suture cavity; and removing the inserter from
the procedural site.
14. The method as recited in claim 13, and further comprising a
step of trimming the free suture ends.
15. The method as recited in claim 13, wherein the removing step
includes a step of physically separating the inserter from the
anchor implant.
Description
BACKGROUND OF THE INVENTION
The present invention is generally related to the field of suture
anchors. There are many procedures, such as SLAP (Superior Labrum
from Anterior to Posterior) and Bankart lesion repairs, or
reconstruction of labral tissue to the glenoid rim, in which a
surgeon needs to secure tissue in close contact with bone. Often
the bone surface is roughened, and when tissue is pulled into
intimate contact, the body's healing response will fuse the tissue
and bone together.
This procedure is often accomplished by implanting an anchor,
pre-loaded with a strand of suture, into a hole drilled in the bone
at the desired anchor location. One of the suture ends is then
passed through the soft tissue at the desired location, and the
suture is secured to the anchor by tying a knot.
There are many suture anchor designs on the market today intended
to secure suture, which is passed through soft tissue, to bone.
Most of the anchor designs rely on interference between external
features on the anchor (barbs, ribs, ridges, etc.) and the hole to
provide fixation strength. A high amount of interference results in
a large force required to insert the anchor into the bone. These
large insertion forces (often imparted by a hammer or mallet) can
result in broken anchors, broken insertion tools, or worse, damage
to the bone itself. An important step in the procedure is adding
tension to the suture to pull the captured tissue into intimate
contact with the bone. Many anchors can change the tension in the
suture during deployment, which requires the surgeon to estimate
how much tension will be added during the final installation step.
This can result in under- or over-tensioning of the tissue against
the bone. The final step of securing the suture and tissue--tying a
knot--has been shown to be a common source of anchor failure. It is
also a step that requires a great deal of practice and skill by the
surgeon and time during the procedure itself.
Since the knot is often problematic for the reasons stated above,
several knotless designs have recently been developed. Some of
these are described below:
The Bioknotless.TM. anchor by DePuy Mitek is a simple anchor which
is loaded with a loop of suture secured to the anchor with a knot.
The loop is passed through the tissue, then the loop must be hooked
in a groove at the tip of the anchor. This step can be tedious and
difficult, depending on the angle of approach to the hole. Finally,
the anchor is tapped into the hole in the bone. The final tension
on the suture loop and attached tissue is controlled by the anchor
insertion depth. This requires the surgeon to drill a hole deep
enough to achieve sufficient tension. If the bite of tissue through
which suture is passed is smaller than expected or achievable, the
anchor may reach the bottom of the hole before enough tension is
placed on the tissue. This results in the tissue not being pulled
firmly against the bone surface and may result in inferior
long-term repair strength. Depending on the angle of approach and
the location on the bone (such as inferior on the glenoid), it may
be impossible to drill a deep enough hole to achieve the desired
tension.
Arthrocare has developed the LabraLock P.TM. anchor. This two-part
anchor, made from PEEK (Polyetheretherketone), secures two strands
of suture (the strands which form the loop that is passed through
the tissue) between the anchor and the bone, and the other two
strands (the free ends of suture) between the anchor's inner shaft
and the outer, tube portion. The outer tube portion has barbs which
secure the anchor in the bone via an interference fit.
The PushLock.TM. anchor, by Arthrex, is also a two-part anchor. The
tip of the anchor has an eyelet through which the suture legs are
loaded. This tip is placed at the bottom of a hole drilled into the
bone. At this point, the surgeon may adjust the tension on the
suture, thereby pulling the tissue closer to the surface of the
bone. When the tension is deemed correct, the rear portion of the
anchor is driven into the hole. This rear portion is a length of
tube which has circumferential barbs on its outer diameter which
provide interference to anchor the device in the hole. Since the
barbed portion of the anchor is a full cylinder, it can require a
great deal of force to insert into a smaller diameter hole,
especially in hard bone.
The ConMed Ultrafix Knotless Minimite.TM. anchor is a knotless
anchor made of metal, which many surgeons do not want to deploy
within a joint. If the anchor were to pull out of the bone, the
metal could cause a great deal of damage rubbing against the
articular surfaces--e.g. the humeral head and glenoid.
Smith & Nephew has marketed the KINSA.TM. suture anchor. It is
a knotless design made of PEEK which is tapped into a pre-drilled
hole in the bone. The anchor is preloaded with suture tied in a
one-way sliding knot within the anchor body, which allows the
surgeon to adjust the tension after the anchor has been
deployed.
SUMMARY OF THE INVENTION
The anchor described in the current invention incorporates several
features which make it simple and consistent for the surgeon to
implant. First, the anchor contains no metal which can damage the
articular surfaces in the joint if it were to be accidentally
pulled out of the bone. Second, the current designs allow the
surgeon to adjust the tension on the suture strands, thus
approximating the captured tissue to the anchor location prior to
securing the anchor and suture. Additionally, when the anchor is
locked into the bone, the tension on the suture and captured tissue
does not change.
Another advantage of the current designs is that they eliminate the
need for the surgeon to tie a knot. The performance of the knot is
dependent upon many factors--the skill of the surgeon, the type of
suture material, the ease of access to the knot location, etc.
Tying a secure knot often requires several knots, such as a Duncan
Loop backed up by alternating half-hitches. Each of these must be
pulled tight with a knot pusher to secure them properly. Securing
the suture between the anchor and bone is much less time consuming
and less prone to surgeon error or variability.
The screw-lock design disclosed herein anchors firmly into the bone
upon insertion. This allows the surgeon to apply the proper tension
without concern that the implant will move or change positions
during the tensioning procedure. Once the proper tension is
achieved, the suture is locked into place within the anchor.
The two-part wedge design disclosed herein requires less force to
insert over most of the insertion depth to deploy the anchor. This
can be especially important in hard bone. A significant portion of
the holding force of the anchor, especially immediately after
implantation, comes from the interference between the bone and the
anchor. Interference is achieved by inserting an anchor into a hole
of smaller diameter. As the difference between the hole diameter
and the anchor diameter increases, the force required to insert the
anchor into the hole becomes greater. By utilizing a two-part wedge
design, the fully deployed diameter is not achieved until the two
pieces of the wedge are fully engaged. This means that a high
insertion force is only required over a very small depth of anchor
insertion, just before the anchor is fully deployed. From the
perspective of the surgeon, this means not having to tap as hard on
the anchor over the full length of the anchor. Not having to tap as
hard results in a lower chance of breaking the anchor, insertion
tool, or doing damage to the bone.
More particularly, there is provided an anchoring system for
securing suture to bone, which comprises an implant having a suture
securing portion, a distal tip, and external surface features for
securing the implant within surrounding bone. A proximal member is
provided, which is movable distally to engage the implant and to
fix the suture in place within the implant and relative to the
bone. An inserter is removably connected to a proximal end of the
implant. In some embodiments of the invention, the proximal member
comprises a screw member. In other embodiments, the proximal member
comprises a wedge member. The suture securing portion may comprise,
for example, a suture eyelet or suture cleat.
The anchoring system may further comprise an engagement tube for
coupling the proximal member and the implant to the inserter, and a
handle portion connected to a proximal end of the inserter.
Internal surface texturing may be disposed within the implant at a
pinch point within the implant, for improving suture retention
after fixation. In some embodiments, a suture channel is disposed
on an external surface of the implant for permitting the suture to
slide freely along the external surface for tissue tensioning. An
internal thread may be disposed in the implant.
In some aspects of the invention, the implant may further comprise
an internal suture cavity having a tapered surface, wherein one leg
of a length of suture running through the implant extends along an
external side of the implant, and a second leg of the length of
suture is compressed against the proximal member and along the
tapered edge of the internal suture cavity.
In the proximal wedge embodiments of the invention, the implant and
the proximal wedge have mating surfaces which lock together when
the implant and the proximal wedge are fully engaged. Snap features
are provided for securing the mating surfaces together, and a
suture channel is preferably disposed on one of the mating
surfaces.
In another aspect of the invention, there is disclosed a method for
securing suture to bone, which comprises drilling a hole in a
desired portion of bone at a desired procedural site, passing a
strand of suture through a portion of soft tissue to be
approximated to the portion of bone, and extending the free suture
ends proximally from the soft tissue. The suture is loaded into an
anchor implant. Using an inserter, on a distal end of which is
attached the anchor implant, the anchor implant is manipulated into
the bone hole. The suture is then tensioned to a desired level by
pulling on the free suture ends, after the anchor implant is
positioned in the bone hole. The free suture ends are wrapped about
a suture cleat on an inserter handle once the desired tension level
is achieved. A proximal anchor component is moved distally to
engage with a distal anchor component to lock the anchor in place
within the bone hole, and to lock the suture in place within the
anchor. Then, the inserter is removed from the procedural site.
Afterwards, the free ends of the suture are trimmed flush. The
inserter removing step preferably includes a step of physically
separating the inserter from the anchor implant.
The invention, together with additional features and advantages
thereof, may best be understood by reference to the following
description taken in conjunction with the accompanying illustrative
drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a distal end view of one embodiment of a "suture first"
suture-to-bone implantable anchor constructed in accordance with
the principles of the present invention;
FIG. 2 is a view similar to FIG. 1, after suture has been snared by
the inventive device and pulled proximally through an eyelet in the
implant;
FIG. 3 is a view similar to FIGS. 1 and 2, showing the inventive
device being inserted into a drilled bone hole;
FIG. 4 is a view similar to FIG. 3, illustrating the inventive
device after it has been advanced to a distal end of the bone
hole;
FIG. 5 is a view similar to FIGS. 3 and 4, illustrating the device
after the suture has been tensioned by the practitioner to
approximate the captured tissue to the anchor location;
FIG. 6A is a plan view illustrating an inserter for use with the
implant of FIGS. 1-5;
FIG. 6B is a detail view of the portion denoted by circle B in FIG.
6A;
FIG. 6C is a detail view of the portion denoted by circle A in FIG.
6A;
FIG. 6D is a cross-sectional view taken along lines 6D-6D in FIG.
6C;
FIG. 7A is an isometric view of the insertion shaft forming a
portion of the inserter illustrated in FIG. 6A;
FIG. 7B is a plan view of the insertion shaft of FIG. 7A;
FIG. 7C is a plan view similar to FIG. 7B, rotated approximately 90
degrees;
FIG. 7D is a cross-sectional view taken along lines 7D--7D of FIG.
7B;
FIG. 7E is a cross-sectional view taken along lines 7E--7E of FIG.
7C;
FIG. 7F is a top end view of the inserter shown in FIG. 7B;
FIG. 7G is a top end view of the inserter shown in FIG. 7C;
FIG. 7H is a bottom end view of the inserter shown in FIG. 7B;
FIG. 8A is an isometric view of a mating screw used in connection
with the embodiment of FIG. 1;
FIG. 8B is a plan view of the screw of FIG. 8A;
FIG. 8C is a cross-sectional view taken along lines 8C--8C of FIG.
8B;
FIG. 9 is an exploded view of the suture anchor and screw of the
embodiment of FIGS. 1-8C;
FIG. 10A is an isometric view of a modified embodiment of the
inventive implant;
FIG. 10B is a plan view of the implant of FIG. 10A;
FIG. 10C is a plan view similar to FIG. 10B, rotated approximately
90 degrees relative to FIG. 10B;
FIG. 10D is a cross-sectional view taken along the lines 10D--10D
of FIG. 10B;
FIG. 10E is a plan view similar to FIG. 10B, rotated approximately
180 degrees relative to FIG. 10B;
FIG. 10F is a top view of the implant illustrated in FIG. 10C;
FIG. 11A is a plan view similar to FIG. 10E, after suture has been
deployed therein;
FIG. 11B is a cross-sectional view taken along lines 11B--11B of
FIG. 11A;
FIG. 12 is a plan view of another modified embodiment of an
inserter and suture anchor constructed in accordance with the
principles of the present invention;
FIG. 13A is an isometric view of the distal tip of the suture
anchor of FIG. 12;
FIG. 13B is a view similar to FIG. 13A illustrating the anchor
loaded with suture;
FIG. 14 is an isometric view showing the distal tip of the suture
anchor of FIGS. 12-13B as it is inserted into a drilled hole
(socket) in bone;
FIG. 15 is an isometric view similar to FIG. 14, wherein the anchor
components have been engaged;
FIG. 16 is an isometric view similar to FIG. 15, wherein the anchor
has been fully deployed and the inserter removed;
FIG. 17 is an exploded side view of the two components of the
anchor of the inserter tip of FIG. 12, prior to deployment with a
bone socket;
FIG. 18 is a side view similar to FIG. 17 wherein the anchor
components of the embodiment of FIG. 12 are fully deployed;
FIG. 19A is an isometric view of one component of the inventive
anchor of FIG. 12;
FIG. 19B is a similar view to that of FIG. 19A, illustrating the
other major component of the anchor of FIG. 12;
FIG. 20A is a top isometric view of the proximal wedge of the
embodiment of FIGS. 12-19B;
FIG. 20B is a bottom isometric view of the proximal wedge of FIG.
20A;
FIG. 21 is an isometric view of the inserter distal end of the
embodiment of FIGS. 12-20B;
FIG. 22 is an isometric view of the inserter handle of the
embodiment of FIGS. 12-20B;
FIG. 23A is a cross-sectional side view of a modified embodiment of
the inserter tip shown in FIGS. 12-21, with the wire lock in an
unlocked position;
FIG. 23B is a cross-sectional side view of the embodiment of FIG.
23A, wherein the wire lock is in a locked position;
FIG. 24 is an isometric view of still another modified embodiment
of the inserter tip of FIGS. 12-21;
FIG. 25 is an isometric cross-sectional view of the inserter tip of
FIG. 24;
FIG. 26A is a side cross-sectional view of yet another modified
embodiment of the inserter tip of FIGS. 12-21, wherein the flex arm
is in a locked position;
FIG. 26B is view similar to FIG. 26A, wherein the flex arm is in an
unlocked position;
FIG. 27 is an isometric view of still another embodiment of the
inserter tip of FIGS. 12-21; and
FIG. 28 is a cross-sectional view of the distal portion of the
embodiment of FIG. 27.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now more particularly to the drawings, there is shown in
FIGS. 1-5 the distal end of a "suture first" suture to bone
implantable anchoring device 10. The device 10 comprises an
inserter 12, and an implant 14 loaded on the tip of the inserter
12. Suture 16 is disposed along the inserter 12, as shown in FIG.
1, for example, and through the implant 14, with a loop 18 of
suture extending therefrom. This loop 18 is the loop of suture
which would extend through the tissue to be approximated to the
bone, which is not shown, for clarity. Also not shown in this
figure is a suture snare that is used to pull the suture loop 18
into a suture eyelet in the middle of the implant 14, which is
illustrated and described below. The snare may comprise a loop of
nitinol wire or suture, insert molded into a plastic pull-tab (not
shown) which may be mounted on the shaft of the inserter 12. Once
the suture strands are placed into the suture snare, the pull-tab
is removed from the inserter shaft and pulled proximally to ensnare
the suture strands and pass them through the eyelet in the implant.
FIG. 2 illustrates the inserter 12 and implant 14 after the suture
has been passed through the implant eyelet. In accordance with a
method of the invention, the inserter 12 of FIG. 1 is slid along
the suture 16 distally and through an arthroscopic portal into the
patient's body, in the vicinity of the desired procedural site. The
distal tip of the implant is then inserted into a hole or tunnel 20
(FIG. 3) which has been pre-drilled in a selected bone portion 22,
and advanced until it is flush with the bottom of the hole 20 (FIG.
4). At this point, the surgeon can pull on the free ends of the
suture 16, which have remained outside of the arthroscopic portal
(not shown), to tension the suture 16 and thereby approximate
captured tissue (not shown) to the anchor location.
FIGS. 6A-6D illustrate an embodiment of a simple insertion device
which may be used in conjunction with the device 10. It is noted
that the implant 14 may be comprised of a biocompatible material,
such as PEEK. FIG. 6C illustrates the implant in its suture-loaded
configuration, ready for insertion into the bone drill hole and
ready for deployment. As shown in FIG. 6D, the implant further
comprises a screw 24, which is retained only partially within the
implant 14 prior to deployment. An engagement tube 26 is also
disposed within the implant 14. Its purpose is to tighten the screw
24, and to couple the screw and implant 14 to the insertion device
12. The tip of the engagement tube 26 is threaded to engage with
the top of the screw 24. The inserter or insertion device 12
comprises an insertion shaft 28. The insertion shaft functions to
transfer a load from the insertion device 12 to the top of the
implant 14, thereby allowing the implant 14 to be hammered or
pushed into the drill hole 20. The insertion shaft 28 engages with
the engagement tube 26 by means of a threaded engagement 30 between
the insertion shaft 28 and the engagement tube 26 at a proximal end
of the inserter 12 (FIG. 6B and Detail B of FIG. 6A). The thread
between the insertion shaft and the engagement tube is in a 1:1
ratio with the PEEK screw 24 in the implant, so that the travel
distance of the PEEK screw 24 and the engagement tube 26 remains
the same. Moreover, the travel distance is adjustably limited by
the threaded portion 30 shown in FIG. 6B.
Proximal to the threaded portion 30, is a handle portion 32, for
permitting manipulation and rotation of the device 10, as
desired.
There are two potential modes of removal of the insertion device 12
from the implant 14, after deployment. In one such mode, after
deployment of the implant by tightening the screw 24, the screw can
be purposely over-tightened, thus breaking the screw 24 off from
the implant 14. Testing has shown that the screw 24 does not need
to be made specifically "frangible" for this method to work
repeatedly, as torsional stress are always the highest in the PEEK
screw 24 at the tip of the engagement tube 26.
Another mode for removal assumes that after deployment or
tightening of the screw 24, the frictional forces of the suture 16
against the screw 24 are high enough to prevent the screw 24 from
loosening while the engagement tube 26 is rotated in the
anti-deployment direction to loosen its threads from the PEEK screw
24. Of course, other suitable removal modes may be utilized as
well.
FIGS. 7A-7H illustrate in greater detail constructional features of
the implant 14. In particular, the implant 14 comprises internal
surface texturing 34 at a pinch point within the implant, for
improving suture retention after fixation. The internal surface
texturing may comprise spikes, knurling, or other known biting
surfaces of that nature.
A suture eyelet or cleat 36 is provided within the implant. The
suture loads through the eyelet with the use of a suture snare, as
was described above. During deployment, the suture get pushed
within the cleat, which bites into the suture for retention. A
suture channel 38 allows the suture to slide freely along the
external walls of the implant 14 for tissue tensioning. In
practice, the implant 14 is inserted into the bone tunnel 20, and
desired tension is achieved by manually pulling on the suture
strands. Once the desired tension is achieved, the screw 24 locks
the suture in place.
An internal thread 40 is provided within the PEEK implant 14. The
mating screw 24 creates a pinch force, locking the suture into
place after tensioning. The thread also serves as a retention
mechanism for attaching the implant and screw to the insertion
device 12. A plurality of frustoconical surfaces or barbs 42 serve
to retain the implant and resist pullout from adjacent bone.
FIGS. 8A-8C illustrate in greater detail the mating screw 24. As
noted above, tightening of the screw within the implant 14 locks
the suture into place by pinching it against the bottom of the
anchor and also by forcing it into the suture cleats connected to
the suture eyelet. The bottom 44 of the screw 24 may be knurled,
cupped, or pointed to increase the pinching force that locks the
suture into place.
FIG. 9 is an exploded view of the implant 14 and screw 24, shown,
for clarity, without suture and not attached to the insertion
device 12.
A modified embodiment of the implant 14 is illustrated in FIGS.
10A-11C. In this embodiment, rather than having the suture being
pinched solely at the bottom of the implant 14, this embodiment
features one leg 16a of the suture running on the external side of
the implant, while the other leg 16b of the suture remains inside
of the implant to be compressed against the screw 24 and along the
tapered edge of a suture cavity 46. The implant is threaded, as in
the prior embodiment, but because of the tapered internal cavity 46
inside one half of the implant, the thread is not fully
circumferential. Instead, it extends downwardly along a "C" shaped
screw portion 48. The PEEK screw 24 still couples the implant to
the inserter, in the same manner as the device of FIGS. 1-9. The
internal cavity is tapered to allow the suture to slide freely for
tensioning up until the point that the screw is tightened fully. A
single suture channel 50 permits the suture to slide freely through
the suture eyelet 36, after placing the implant 14 and suture into
the drill hole 20 in the bone 22. Upon tightening of the screw 24,
the suture 16 is effectively squeezed along the internal tapered
cavity 46 and screw 24, thus locking the suture in place.
Returning again to a discussion of a method of use of the inventive
device 10, once the proper tension is achieved, the suture ends can
be wrapped around cleats on the inserter handle 32 to maintain the
desired tension. The surgeon then removes a safety pin from the
inserter 12 and rotates the main handle portion 32 clockwise while
holding a small inserter knob stationary. This drives the screw 24
inside the implant towards a pinch point, pushing the suture
strands 16 into suture cleats 36 in the implant 14 while pinching
the suture firmly at the inside bottom of the implant to prevent it
from slipping. The handle is rotated until the proximal end of the
screw (threaded inside the engagement tube) shears, releasing the
inserter from the implant site. An alternate method of releasing
the inserter would be to rotate the inserter handle
counter-clockwise at the end of the screw's travel, while holding
the small knob stationary. At this point, the friction of the
suture against the PEEK screw prevents the screw from unscrewing.
However, since the handle is rotated counter-clockwise, the
inserter would unscrew itself from the end of the PEEK implant
screw thus releasing it from the site of implant.
Now with reference to FIG. 12, another embodiment of an inventive
suture anchoring device 52 is illustrated. The device 52 is a
simple to insert suture anchor which permits adjustment of suture
tension prior to deployment, does not change the tension on the
suture (and, as a result, the captured tissue) when it is deployed,
does not require a knot to secure the suture, and does not require
high insertion forces over the entire depth of insertion into the
bone socket. The device 52 comprises a distal tip 54, a proximal
wedge 56, and an inserter 58, as well as a handle 60. As shown in
FIGS. 13A-16, the inserter 58 further comprises an inserter tip 62.
A suture eyelet 64 is disposed at a distal end of the distal tip
54. Suture 66 may be loaded onto the device 52, in a manner that
will be described below.
Most anchors are supplied pre-loaded with suture passing through an
eyelet in the anchor. Such a design is an "anchor first" design,
wherein the surgeon drills a hole in a desired location, installs
the anchor in the hole, passes one of the free ends of suture
through the tissue, and then ties a knot to secure the suture and
attached tissue to the anchor. However, the present invention is a
"suture first" approach. Again, the surgeon, in a representative
procedure performed in accordance with the invention, drills a hole
68 in a desired portion of bone 70 (FIG. 14), in a selected
anchoring location. Then, a strand of suture 66 is passed through
the tissue (not shown) with the surgeon's choice of suture passing
tools. The free suture legs 66a, 66b are then brought out of the
patient's body for loading into the suture anchor. FIG. 12 shows
the suture anchor components 54, 56 pre-loaded onto the disposable
inserter tool 58. The suture anchor comprises two separate parts,
the distal tip 54 and the proximal wedge 56, which engage and lock
together when deployed within the bone socket 68.
FIG. 13A shows a close-up of the suture anchor components loaded on
the inserter tip 62. The suture 66 is shown loaded into the anchor
in FIG. 13B. The two free ends 16a, 16b of the suture 66 are passed
through the eyelet 64 in the distal tip 54. This step can be aided
by the use of a nitinol wire snare or suture snare to pull the ends
through the eyelet. The loop shown is the loop which passes through
the tissue. The tip of the inserter, with the anchor in place, is
then slid down the suture strands into the arthroscopic working
space. The distal tip 54 is inserted to the bottom of the drilled
hole or socket 68, as shown in FIG. 14. At this point, the surgeon
can pull on the free ends 66a, 66b of the suture, which are still
outside the patient's body, to add tension and approximate the
captured tissue to the anchor location. Once the proper tension is
achieved, the suture ends can be wrapped around suture cleats 72 on
the handle 60 to maintain the desired tension.
Once the proper tension is achieved, the surgeon taps on the end of
the inserter handle 60 to push the proximal wedge 56 into the hole
68, as shown in FIG. 15. When the proximal wedge is fully seated,
the two anchor components 54, 56 lock together within the socket
68.
Finally, as shown in FIG. 16, the inserter tool 58 is removed, and
the free ends of the suture are trimmed flush.
FIG. 17 illustrates a side view of the two components 54 and 56 of
the anchor 52 on the inserter tip 62, prior to deployment within
the bone socket 68. The exterior surface of the anchor components
comprises barbs 74, although alternative surface features may also
be employed for ensuring a solid engagement between the anchor and
the interior bony surface of the hole 68.
FIG. 18 shows the two components 54, 56 of the anchor in a deployed
state. The proximal wedge 56 has been driven against the distal tip
54, locking the two pieces together with three sets of snap
features 76. The primary mating surface 78 between the two
components 54, 56 is at an angle with respect to the axial
orientation of the respective components. This results in the
components wedging apart and providing greater interference when
fully engaged in the bone hole 68.
FIGS. 19A and 19B illustrate details of the distal tip 54. The
front of the distal tip contains the eyelet 64, through which the
suture ends are passed. The eyelet is closed, so that the suture
legs 66a and 66b cannot come free of the anchor after they are
loaded. The top surface includes a channel 80 to accept the
inserter tip 62. In a preferred design, the channel 80 is
hourglass-shaped to aid in holding the distal tip 54 onto the
matching contour of the inserter tip 62, and to prevent rotation of
the components with respect to the inserter. The bottom surface of
the distal tip includes a suture channel 82 through which the
suture ends pass. This channel 82 allows room for the free suture
legs to slide between the anchor and the bone socket when the
distal tip is placed at the bottom of the hole 68. When the anchor
is deployed, the distal tip is pressed against the side of the bone
socket, reducing the size of this channel and compressing the
suture between the anchor and the bone.
Two views of the proximal wedge 56 are shown in FIGS. 20A and 20B.
This component contains ;the same hourglass-shaped channel 80 to
hold the part onto the inserter tip 62 and prevent rotation. There
are also corresponding snap feature notches which engage with the
snap features 76 on the distal tip to lock the two parts together
when deployed.
The distal end of the inserter 58, illustrated in FIG. 21, includes
two components to deploy the anchor 10. The inserter tip 62 has an
hourglass profile 86. The hourglass shape helps to secure and
prevent rotation of the anchor components on the tip. Just proximal
to the tip is an insertion sleeve 88. When the end of the inserter
is tapped with a mallet, the insertion sleeve 88 moves distally to
drive the proximal wedge 56 into the hole 68 and engage with the
distal tip 54.
The handle 60 of the inserter is shown in FIG. 22. The distal end
of the handle includes a set of suture cleats 72. After a proper
suture tension has been achieved, the suture may be wrapped around
the cleats 72 to secure them and prevent further movement. The
inserter handle 60 is fixed relative to the hourglass-shaped
inserter tip 62. At the proximal end of the handle 60 is a knob 90.
The knob is fixed relative to the insertion sleeve 88. When the
knob 90 is tapped with a hammer, it drives the insertion sleeve 88
and the proximal wedge 56 forwardly with respect to the handle,
which the surgeon is holding, and the distal tip 54. The knob 90
moves flush with the end of the handle when the two anchor
components 54, 56 are fully engaged.
There are several variations from the above described embodiment of
FIGS. 12-22 which may be incorporated, if desired. For example,
with respect to the implant, the external holding features of the
anchor components (shown in the depicted embodiment as the
circumferential barbs 74) could be a number of different shapes,
depending upon desired performance and location of the anchor. The
circumferential features may be ridges, with equal angles on both
the leading and trailing edges, especially on the distal tip 54.
This could aid in preventing the distal tip from moving in either
direction, distally or proximally, after deployment. The barbs may
be interrupted to reduce insertion forces in hard bone or to
encourage tissue ingrowth after insertion.
In addition, the blind hole in the distal tip could include
features which aid in holding the distal tip onto the inserter tip.
Three of these potential variations are discussed below.
FIGS. 23A and 23B show a variation of the inserter tip 62 and
implant which offers improved retention of the distal tip on the
inserter tip. For this variation, a transverse hole 92 has been
added to the distal tip, which intersects the hourglass-shaped
blind hole. The inserter tip shaft has been modified to include a
central hole down the center with a ramp feature 94 at the distal
end of the part. A wire 96 is located within this central hole.
This position is the "unlocked" position, and the inserter tip can
be pulled to the right and out of the distal tip. When the wire is
slid distally (to the left) within the inserter tip, it is diverted
by the ramp feature and forced to extend proud of the surface of
the inserter tip, slightly into the transverse bole in the distal
tip (FIG. 23B). This is the "locked" position, which does not allow
the inserter tip to be pulled to the right and out of the distal
tip.
Another variation which serves the same purpose is shown in FIGS.
24 and 25. FIG. 24 shows a modification to the end of the inserter
tip. In this design, the tip has a round cross-section where the
distal tip is held. Just proximal to the round section, the
inserter tip has the same hourglass shape as shown in the afore
described embodiments.
FIG. 25 shows a cross-section of the inserter tip, distal tip, and
proximal wedge. As can be seen in this view, the most distal end of
the inserter tip is threaded over a small portion of its length.
The hole in the distal tip into which the inserter tip fits
includes a mating threaded portion 98. This threaded portion serves
to secure the distal tip to the end of the inserter tip. When the
proximal wedge is deployed, it is pushed beyond the
hourglass-shaped portion of the inserter tip. Once in the position
shown, the inserter tip can be rotated to unscrew the threads from
the distal tip and removed.
Yet another variation of the inserter tip is shown in FIGS. 26A and
26B. The version illustrated requires two transverse holes in the
distal tip which intersect the hourglass-shaped blind hole. This
distal end of the inserter tip includes a central hole through
which a wire can pass, a thin slot 100 cut through the end, and two
small bumps. As shown in FIG. 26A, the wire is positioned at the
end of the inserter tip. In this position, the distal tip cannot be
pulled to the right and out of the distal tip. When the wire is
pulled to the right (FIG. 26B), the end of the inserter tip is
allowed to flex at the thin slot 100, which flexes the bumps out of
the transverse holes and allows the inserter tip to pull out of the
distal tip.
FIGS. 27 and 28 illustrate another variation of a method of locking
the distal tip onto the end of the inserter tip. In this
embodiment, the external, distal end of the inserter tip comprises
the hourglass profile of prior embodiments. However, the inserter
tip is cannulated, through which an inner wire passes. The inner
wire has a threaded portion 104 which extends beyond the end of the
inserter tip. This threaded portion threads into an internally
threaded hole in the distal tip. FIG. 28 shows, specifically, a
detailed cross-section of the distal tip, threaded inner wire, and
inserter tip. The threads of the inner wire and distal tip engage
to secure the distal tip on the end of the assembly. To unlock, the
inner wire is rotated to disengage the threads, and the inserter
tip can be removed. The threaded portion of the inner wire can have
threads which are the same diameter as the inner wire, or,
alternative, can have either a smaller or a larger diameter.
Accordingly, although an exemplary embodiment of the invention has
been shown and described, it is to be understood that all the terms
used herein are descriptive rather than limiting, and that many
changes, modifications, and substitutions may be made by one having
ordinary skill in the art without departing from the spirit and
scope of the invention, which is to be limited only in accordance
with the following claims.
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